Commit | Line | Data |
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3bd94003 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * Copyright (C) 2003 Sistina Software | |
891ce207 | 4 | * Copyright (C) 2006 Red Hat GmbH |
1da177e4 LT |
5 | * |
6 | * This file is released under the GPL. | |
7 | */ | |
8 | ||
4cc96131 | 9 | #include "dm-core.h" |
952b3557 | 10 | |
586e80e6 | 11 | #include <linux/device-mapper.h> |
1da177e4 LT |
12 | |
13 | #include <linux/bio.h> | |
10f1d5d1 | 14 | #include <linux/completion.h> |
1da177e4 LT |
15 | #include <linux/mempool.h> |
16 | #include <linux/module.h> | |
17 | #include <linux/sched.h> | |
18 | #include <linux/slab.h> | |
a765e20e | 19 | #include <linux/dm-io.h> |
1da177e4 | 20 | |
f1e53987 MP |
21 | #define DM_MSG_PREFIX "io" |
22 | ||
23 | #define DM_IO_MAX_REGIONS BITS_PER_LONG | |
24 | ||
891ce207 | 25 | struct dm_io_client { |
6f1c819c KO |
26 | mempool_t pool; |
27 | struct bio_set bios; | |
891ce207 HM |
28 | }; |
29 | ||
f1e53987 MP |
30 | /* |
31 | * Aligning 'struct io' reduces the number of bits required to store | |
32 | * its address. Refer to store_io_and_region_in_bio() below. | |
33 | */ | |
1da177e4 | 34 | struct io { |
e01fd7ee | 35 | unsigned long error_bits; |
1da177e4 | 36 | atomic_t count; |
891ce207 | 37 | struct dm_io_client *client; |
1da177e4 LT |
38 | io_notify_fn callback; |
39 | void *context; | |
bb91bc7b MP |
40 | void *vma_invalidate_address; |
41 | unsigned long vma_invalidate_size; | |
f1e53987 | 42 | } __attribute__((aligned(DM_IO_MAX_REGIONS))); |
1da177e4 | 43 | |
952b3557 MP |
44 | static struct kmem_cache *_dm_io_cache; |
45 | ||
c8b03afe HM |
46 | /* |
47 | * Create a client with mempool and bioset. | |
48 | */ | |
bda8efec | 49 | struct dm_io_client *dm_io_client_create(void) |
c8b03afe | 50 | { |
c8b03afe | 51 | struct dm_io_client *client; |
e8603136 | 52 | unsigned min_ios = dm_get_reserved_bio_based_ios(); |
6f1c819c | 53 | int ret; |
c8b03afe | 54 | |
d3775354 | 55 | client = kzalloc(sizeof(*client), GFP_KERNEL); |
c8b03afe HM |
56 | if (!client) |
57 | return ERR_PTR(-ENOMEM); | |
58 | ||
6f1c819c KO |
59 | ret = mempool_init_slab_pool(&client->pool, min_ios, _dm_io_cache); |
60 | if (ret) | |
c8b03afe HM |
61 | goto bad; |
62 | ||
6f1c819c KO |
63 | ret = bioset_init(&client->bios, min_ios, 0, BIOSET_NEED_BVECS); |
64 | if (ret) | |
c8b03afe HM |
65 | goto bad; |
66 | ||
67 | return client; | |
68 | ||
69 | bad: | |
6f1c819c | 70 | mempool_exit(&client->pool); |
c8b03afe | 71 | kfree(client); |
6f1c819c | 72 | return ERR_PTR(ret); |
c8b03afe HM |
73 | } |
74 | EXPORT_SYMBOL(dm_io_client_create); | |
75 | ||
c8b03afe HM |
76 | void dm_io_client_destroy(struct dm_io_client *client) |
77 | { | |
6f1c819c KO |
78 | mempool_exit(&client->pool); |
79 | bioset_exit(&client->bios); | |
c8b03afe HM |
80 | kfree(client); |
81 | } | |
82 | EXPORT_SYMBOL(dm_io_client_destroy); | |
83 | ||
1da177e4 LT |
84 | /*----------------------------------------------------------------- |
85 | * We need to keep track of which region a bio is doing io for. | |
f1e53987 MP |
86 | * To avoid a memory allocation to store just 5 or 6 bits, we |
87 | * ensure the 'struct io' pointer is aligned so enough low bits are | |
88 | * always zero and then combine it with the region number directly in | |
89 | * bi_private. | |
1da177e4 | 90 | *---------------------------------------------------------------*/ |
f1e53987 MP |
91 | static void store_io_and_region_in_bio(struct bio *bio, struct io *io, |
92 | unsigned region) | |
1da177e4 | 93 | { |
f1e53987 MP |
94 | if (unlikely(!IS_ALIGNED((unsigned long)io, DM_IO_MAX_REGIONS))) { |
95 | DMCRIT("Unaligned struct io pointer %p", io); | |
96 | BUG(); | |
97 | } | |
98 | ||
99 | bio->bi_private = (void *)((unsigned long)io | region); | |
1da177e4 LT |
100 | } |
101 | ||
f1e53987 MP |
102 | static void retrieve_io_and_region_from_bio(struct bio *bio, struct io **io, |
103 | unsigned *region) | |
1da177e4 | 104 | { |
f1e53987 MP |
105 | unsigned long val = (unsigned long)bio->bi_private; |
106 | ||
107 | *io = (void *)(val & -(unsigned long)DM_IO_MAX_REGIONS); | |
108 | *region = val & (DM_IO_MAX_REGIONS - 1); | |
1da177e4 LT |
109 | } |
110 | ||
111 | /*----------------------------------------------------------------- | |
112 | * We need an io object to keep track of the number of bios that | |
113 | * have been dispatched for a particular io. | |
114 | *---------------------------------------------------------------*/ | |
97e7cdf1 | 115 | static void complete_io(struct io *io) |
1da177e4 | 116 | { |
97e7cdf1 JT |
117 | unsigned long error_bits = io->error_bits; |
118 | io_notify_fn fn = io->callback; | |
119 | void *context = io->context; | |
1da177e4 | 120 | |
97e7cdf1 JT |
121 | if (io->vma_invalidate_size) |
122 | invalidate_kernel_vmap_range(io->vma_invalidate_address, | |
123 | io->vma_invalidate_size); | |
bb91bc7b | 124 | |
6f1c819c | 125 | mempool_free(io, &io->client->pool); |
97e7cdf1 JT |
126 | fn(error_bits, context); |
127 | } | |
1da177e4 | 128 | |
4e4cbee9 | 129 | static void dec_count(struct io *io, unsigned int region, blk_status_t error) |
97e7cdf1 JT |
130 | { |
131 | if (error) | |
132 | set_bit(region, &io->error_bits); | |
1da177e4 | 133 | |
97e7cdf1 JT |
134 | if (atomic_dec_and_test(&io->count)) |
135 | complete_io(io); | |
1da177e4 LT |
136 | } |
137 | ||
4246a0b6 | 138 | static void endio(struct bio *bio) |
1da177e4 | 139 | { |
c897feb3 HM |
140 | struct io *io; |
141 | unsigned region; | |
4e4cbee9 | 142 | blk_status_t error; |
1da177e4 | 143 | |
4e4cbee9 | 144 | if (bio->bi_status && bio_data_dir(bio) == READ) |
1da177e4 LT |
145 | zero_fill_bio(bio); |
146 | ||
c897feb3 HM |
147 | /* |
148 | * The bio destructor in bio_put() may use the io object. | |
149 | */ | |
f1e53987 | 150 | retrieve_io_and_region_from_bio(bio, &io, ®ion); |
c897feb3 | 151 | |
4e4cbee9 | 152 | error = bio->bi_status; |
1da177e4 LT |
153 | bio_put(bio); |
154 | ||
9b81c842 | 155 | dec_count(io, region, error); |
1da177e4 LT |
156 | } |
157 | ||
158 | /*----------------------------------------------------------------- | |
159 | * These little objects provide an abstraction for getting a new | |
160 | * destination page for io. | |
161 | *---------------------------------------------------------------*/ | |
162 | struct dpages { | |
163 | void (*get_page)(struct dpages *dp, | |
164 | struct page **p, unsigned long *len, unsigned *offset); | |
165 | void (*next_page)(struct dpages *dp); | |
166 | ||
cacc7b05 ML |
167 | union { |
168 | unsigned context_u; | |
169 | struct bvec_iter context_bi; | |
170 | }; | |
1da177e4 | 171 | void *context_ptr; |
bb91bc7b MP |
172 | |
173 | void *vma_invalidate_address; | |
174 | unsigned long vma_invalidate_size; | |
1da177e4 LT |
175 | }; |
176 | ||
177 | /* | |
178 | * Functions for getting the pages from a list. | |
179 | */ | |
180 | static void list_get_page(struct dpages *dp, | |
181 | struct page **p, unsigned long *len, unsigned *offset) | |
182 | { | |
183 | unsigned o = dp->context_u; | |
184 | struct page_list *pl = (struct page_list *) dp->context_ptr; | |
185 | ||
186 | *p = pl->page; | |
187 | *len = PAGE_SIZE - o; | |
188 | *offset = o; | |
189 | } | |
190 | ||
191 | static void list_next_page(struct dpages *dp) | |
192 | { | |
193 | struct page_list *pl = (struct page_list *) dp->context_ptr; | |
194 | dp->context_ptr = pl->next; | |
195 | dp->context_u = 0; | |
196 | } | |
197 | ||
198 | static void list_dp_init(struct dpages *dp, struct page_list *pl, unsigned offset) | |
199 | { | |
200 | dp->get_page = list_get_page; | |
201 | dp->next_page = list_next_page; | |
202 | dp->context_u = offset; | |
203 | dp->context_ptr = pl; | |
204 | } | |
205 | ||
206 | /* | |
207 | * Functions for getting the pages from a bvec. | |
208 | */ | |
d73f9907 MP |
209 | static void bio_get_page(struct dpages *dp, struct page **p, |
210 | unsigned long *len, unsigned *offset) | |
1da177e4 | 211 | { |
cacc7b05 ML |
212 | struct bio_vec bvec = bvec_iter_bvec((struct bio_vec *)dp->context_ptr, |
213 | dp->context_bi); | |
214 | ||
215 | *p = bvec.bv_page; | |
216 | *len = bvec.bv_len; | |
217 | *offset = bvec.bv_offset; | |
218 | ||
219 | /* avoid figuring it out again in bio_next_page() */ | |
220 | dp->context_bi.bi_sector = (sector_t)bvec.bv_len; | |
1da177e4 LT |
221 | } |
222 | ||
003b5c57 | 223 | static void bio_next_page(struct dpages *dp) |
1da177e4 | 224 | { |
cacc7b05 ML |
225 | unsigned int len = (unsigned int)dp->context_bi.bi_sector; |
226 | ||
227 | bvec_iter_advance((struct bio_vec *)dp->context_ptr, | |
228 | &dp->context_bi, len); | |
1da177e4 LT |
229 | } |
230 | ||
003b5c57 | 231 | static void bio_dp_init(struct dpages *dp, struct bio *bio) |
1da177e4 | 232 | { |
003b5c57 KO |
233 | dp->get_page = bio_get_page; |
234 | dp->next_page = bio_next_page; | |
cacc7b05 ML |
235 | |
236 | /* | |
237 | * We just use bvec iterator to retrieve pages, so it is ok to | |
238 | * access the bvec table directly here | |
239 | */ | |
240 | dp->context_ptr = bio->bi_io_vec; | |
241 | dp->context_bi = bio->bi_iter; | |
1da177e4 LT |
242 | } |
243 | ||
c8b03afe HM |
244 | /* |
245 | * Functions for getting the pages from a VMA. | |
246 | */ | |
1da177e4 LT |
247 | static void vm_get_page(struct dpages *dp, |
248 | struct page **p, unsigned long *len, unsigned *offset) | |
249 | { | |
250 | *p = vmalloc_to_page(dp->context_ptr); | |
251 | *offset = dp->context_u; | |
252 | *len = PAGE_SIZE - dp->context_u; | |
253 | } | |
254 | ||
255 | static void vm_next_page(struct dpages *dp) | |
256 | { | |
257 | dp->context_ptr += PAGE_SIZE - dp->context_u; | |
258 | dp->context_u = 0; | |
259 | } | |
260 | ||
261 | static void vm_dp_init(struct dpages *dp, void *data) | |
262 | { | |
263 | dp->get_page = vm_get_page; | |
264 | dp->next_page = vm_next_page; | |
93bbf583 | 265 | dp->context_u = offset_in_page(data); |
1da177e4 LT |
266 | dp->context_ptr = data; |
267 | } | |
268 | ||
c8b03afe HM |
269 | /* |
270 | * Functions for getting the pages from kernel memory. | |
271 | */ | |
272 | static void km_get_page(struct dpages *dp, struct page **p, unsigned long *len, | |
273 | unsigned *offset) | |
274 | { | |
275 | *p = virt_to_page(dp->context_ptr); | |
276 | *offset = dp->context_u; | |
277 | *len = PAGE_SIZE - dp->context_u; | |
278 | } | |
279 | ||
280 | static void km_next_page(struct dpages *dp) | |
281 | { | |
282 | dp->context_ptr += PAGE_SIZE - dp->context_u; | |
283 | dp->context_u = 0; | |
284 | } | |
285 | ||
286 | static void km_dp_init(struct dpages *dp, void *data) | |
287 | { | |
288 | dp->get_page = km_get_page; | |
289 | dp->next_page = km_next_page; | |
93bbf583 | 290 | dp->context_u = offset_in_page(data); |
c8b03afe HM |
291 | dp->context_ptr = data; |
292 | } | |
293 | ||
1da177e4 LT |
294 | /*----------------------------------------------------------------- |
295 | * IO routines that accept a list of pages. | |
296 | *---------------------------------------------------------------*/ | |
a3282b43 | 297 | static void do_region(const blk_opf_t opf, unsigned region, |
e6047149 MC |
298 | struct dm_io_region *where, struct dpages *dp, |
299 | struct io *io) | |
1da177e4 LT |
300 | { |
301 | struct bio *bio; | |
302 | struct page *page; | |
303 | unsigned long len; | |
304 | unsigned offset; | |
305 | unsigned num_bvecs; | |
306 | sector_t remaining = where->count; | |
0c535e0d | 307 | struct request_queue *q = bdev_get_queue(where->bdev); |
70d6c400 | 308 | sector_t num_sectors; |
3f649ab7 | 309 | unsigned int special_cmd_max_sectors; |
a3282b43 | 310 | const enum req_op op = opf & REQ_OP_MASK; |
1da177e4 | 311 | |
e5db2980 DW |
312 | /* |
313 | * Reject unsupported discard and write same requests. | |
314 | */ | |
e6047149 | 315 | if (op == REQ_OP_DISCARD) |
cf0fbf89 | 316 | special_cmd_max_sectors = bdev_max_discard_sectors(where->bdev); |
ac62d620 CH |
317 | else if (op == REQ_OP_WRITE_ZEROES) |
318 | special_cmd_max_sectors = q->limits.max_write_zeroes_sectors; | |
a773187e CH |
319 | if ((op == REQ_OP_DISCARD || op == REQ_OP_WRITE_ZEROES) && |
320 | special_cmd_max_sectors == 0) { | |
feb7695f | 321 | atomic_inc(&io->count); |
4e4cbee9 | 322 | dec_count(io, region, BLK_STS_NOTSUPP); |
37527b86 DW |
323 | return; |
324 | } | |
325 | ||
12fc0f49 | 326 | /* |
e6047149 | 327 | * where->count may be zero if op holds a flush and we need to |
d87f4c14 | 328 | * send a zero-sized flush. |
12fc0f49 MP |
329 | */ |
330 | do { | |
1da177e4 | 331 | /* |
f1e53987 | 332 | * Allocate a suitably sized-bio. |
1da177e4 | 333 | */ |
0f5d690f CH |
334 | switch (op) { |
335 | case REQ_OP_DISCARD: | |
ac62d620 | 336 | case REQ_OP_WRITE_ZEROES: |
0f5d690f CH |
337 | num_bvecs = 0; |
338 | break; | |
0f5d690f | 339 | default: |
5f7136db MWO |
340 | num_bvecs = bio_max_segs(dm_sector_div_up(remaining, |
341 | (PAGE_SIZE >> SECTOR_SHIFT))); | |
0f5d690f | 342 | } |
0c535e0d | 343 | |
a3282b43 BVA |
344 | bio = bio_alloc_bioset(where->bdev, num_bvecs, opf, GFP_NOIO, |
345 | &io->client->bios); | |
4f024f37 | 346 | bio->bi_iter.bi_sector = where->sector + (where->count - remaining); |
1da177e4 | 347 | bio->bi_end_io = endio; |
f1e53987 | 348 | store_io_and_region_in_bio(bio, io, region); |
1da177e4 | 349 | |
ac62d620 | 350 | if (op == REQ_OP_DISCARD || op == REQ_OP_WRITE_ZEROES) { |
e5db2980 | 351 | num_sectors = min_t(sector_t, special_cmd_max_sectors, remaining); |
4f024f37 | 352 | bio->bi_iter.bi_size = num_sectors << SECTOR_SHIFT; |
70d6c400 | 353 | remaining -= num_sectors; |
0c535e0d MB |
354 | } else while (remaining) { |
355 | /* | |
356 | * Try and add as many pages as possible. | |
357 | */ | |
1da177e4 LT |
358 | dp->get_page(dp, &page, &len, &offset); |
359 | len = min(len, to_bytes(remaining)); | |
360 | if (!bio_add_page(bio, page, len, offset)) | |
361 | break; | |
362 | ||
363 | offset = 0; | |
364 | remaining -= to_sector(len); | |
365 | dp->next_page(dp); | |
366 | } | |
367 | ||
368 | atomic_inc(&io->count); | |
4e49ea4a | 369 | submit_bio(bio); |
12fc0f49 | 370 | } while (remaining); |
1da177e4 LT |
371 | } |
372 | ||
a3282b43 | 373 | static void dispatch_io(blk_opf_t opf, unsigned int num_regions, |
22a1ceb1 | 374 | struct dm_io_region *where, struct dpages *dp, |
1da177e4 LT |
375 | struct io *io, int sync) |
376 | { | |
377 | int i; | |
378 | struct dpages old_pages = *dp; | |
379 | ||
f1e53987 MP |
380 | BUG_ON(num_regions > DM_IO_MAX_REGIONS); |
381 | ||
1da177e4 | 382 | if (sync) |
a3282b43 | 383 | opf |= REQ_SYNC; |
1da177e4 LT |
384 | |
385 | /* | |
386 | * For multiple regions we need to be careful to rewind | |
387 | * the dp object for each call to do_region. | |
388 | */ | |
389 | for (i = 0; i < num_regions; i++) { | |
390 | *dp = old_pages; | |
a3282b43 BVA |
391 | if (where[i].count || (opf & REQ_PREFLUSH)) |
392 | do_region(opf, i, where + i, dp, io); | |
1da177e4 LT |
393 | } |
394 | ||
395 | /* | |
f00b16ad | 396 | * Drop the extra reference that we were holding to avoid |
1da177e4 LT |
397 | * the io being completed too early. |
398 | */ | |
399 | dec_count(io, 0, 0); | |
400 | } | |
401 | ||
97e7cdf1 JT |
402 | struct sync_io { |
403 | unsigned long error_bits; | |
404 | struct completion wait; | |
405 | }; | |
406 | ||
407 | static void sync_io_complete(unsigned long error, void *context) | |
408 | { | |
409 | struct sync_io *sio = context; | |
410 | ||
411 | sio->error_bits = error; | |
412 | complete(&sio->wait); | |
413 | } | |
414 | ||
891ce207 | 415 | static int sync_io(struct dm_io_client *client, unsigned int num_regions, |
a3282b43 BVA |
416 | struct dm_io_region *where, blk_opf_t opf, struct dpages *dp, |
417 | unsigned long *error_bits) | |
1da177e4 | 418 | { |
97e7cdf1 JT |
419 | struct io *io; |
420 | struct sync_io sio; | |
1da177e4 | 421 | |
a3282b43 | 422 | if (num_regions > 1 && !op_is_write(opf)) { |
1da177e4 LT |
423 | WARN_ON(1); |
424 | return -EIO; | |
425 | } | |
426 | ||
97e7cdf1 JT |
427 | init_completion(&sio.wait); |
428 | ||
6f1c819c | 429 | io = mempool_alloc(&client->pool, GFP_NOIO); |
f1e53987 | 430 | io->error_bits = 0; |
f1e53987 | 431 | atomic_set(&io->count, 1); /* see dispatch_io() */ |
f1e53987 | 432 | io->client = client; |
97e7cdf1 JT |
433 | io->callback = sync_io_complete; |
434 | io->context = &sio; | |
1da177e4 | 435 | |
bb91bc7b MP |
436 | io->vma_invalidate_address = dp->vma_invalidate_address; |
437 | io->vma_invalidate_size = dp->vma_invalidate_size; | |
438 | ||
a3282b43 | 439 | dispatch_io(opf, num_regions, where, dp, io, 1); |
1da177e4 | 440 | |
97e7cdf1 | 441 | wait_for_completion_io(&sio.wait); |
1da177e4 | 442 | |
891ce207 | 443 | if (error_bits) |
97e7cdf1 | 444 | *error_bits = sio.error_bits; |
891ce207 | 445 | |
97e7cdf1 | 446 | return sio.error_bits ? -EIO : 0; |
1da177e4 LT |
447 | } |
448 | ||
891ce207 | 449 | static int async_io(struct dm_io_client *client, unsigned int num_regions, |
a3282b43 | 450 | struct dm_io_region *where, blk_opf_t opf, |
e6047149 | 451 | struct dpages *dp, io_notify_fn fn, void *context) |
1da177e4 LT |
452 | { |
453 | struct io *io; | |
454 | ||
a3282b43 | 455 | if (num_regions > 1 && !op_is_write(opf)) { |
1da177e4 LT |
456 | WARN_ON(1); |
457 | fn(1, context); | |
458 | return -EIO; | |
459 | } | |
460 | ||
6f1c819c | 461 | io = mempool_alloc(&client->pool, GFP_NOIO); |
e01fd7ee | 462 | io->error_bits = 0; |
1da177e4 | 463 | atomic_set(&io->count, 1); /* see dispatch_io() */ |
891ce207 | 464 | io->client = client; |
1da177e4 LT |
465 | io->callback = fn; |
466 | io->context = context; | |
467 | ||
bb91bc7b MP |
468 | io->vma_invalidate_address = dp->vma_invalidate_address; |
469 | io->vma_invalidate_size = dp->vma_invalidate_size; | |
470 | ||
a3282b43 | 471 | dispatch_io(opf, num_regions, where, dp, io, 0); |
1da177e4 LT |
472 | return 0; |
473 | } | |
474 | ||
bb91bc7b MP |
475 | static int dp_init(struct dm_io_request *io_req, struct dpages *dp, |
476 | unsigned long size) | |
c8b03afe HM |
477 | { |
478 | /* Set up dpages based on memory type */ | |
bb91bc7b MP |
479 | |
480 | dp->vma_invalidate_address = NULL; | |
481 | dp->vma_invalidate_size = 0; | |
482 | ||
c8b03afe HM |
483 | switch (io_req->mem.type) { |
484 | case DM_IO_PAGE_LIST: | |
485 | list_dp_init(dp, io_req->mem.ptr.pl, io_req->mem.offset); | |
486 | break; | |
487 | ||
003b5c57 KO |
488 | case DM_IO_BIO: |
489 | bio_dp_init(dp, io_req->mem.ptr.bio); | |
c8b03afe HM |
490 | break; |
491 | ||
492 | case DM_IO_VMA: | |
bb91bc7b | 493 | flush_kernel_vmap_range(io_req->mem.ptr.vma, size); |
581075e4 | 494 | if ((io_req->bi_opf & REQ_OP_MASK) == REQ_OP_READ) { |
bb91bc7b MP |
495 | dp->vma_invalidate_address = io_req->mem.ptr.vma; |
496 | dp->vma_invalidate_size = size; | |
497 | } | |
c8b03afe HM |
498 | vm_dp_init(dp, io_req->mem.ptr.vma); |
499 | break; | |
500 | ||
501 | case DM_IO_KMEM: | |
502 | km_dp_init(dp, io_req->mem.ptr.addr); | |
503 | break; | |
504 | ||
505 | default: | |
506 | return -EINVAL; | |
507 | } | |
508 | ||
509 | return 0; | |
510 | } | |
511 | ||
c8b03afe | 512 | int dm_io(struct dm_io_request *io_req, unsigned num_regions, |
22a1ceb1 | 513 | struct dm_io_region *where, unsigned long *sync_error_bits) |
c8b03afe HM |
514 | { |
515 | int r; | |
516 | struct dpages dp; | |
517 | ||
bb91bc7b | 518 | r = dp_init(io_req, &dp, (unsigned long)where->count << SECTOR_SHIFT); |
c8b03afe HM |
519 | if (r) |
520 | return r; | |
521 | ||
522 | if (!io_req->notify.fn) | |
523 | return sync_io(io_req->client, num_regions, where, | |
a3282b43 | 524 | io_req->bi_opf, &dp, sync_error_bits); |
c8b03afe | 525 | |
581075e4 | 526 | return async_io(io_req->client, num_regions, where, |
a3282b43 | 527 | io_req->bi_opf, &dp, io_req->notify.fn, |
e6047149 | 528 | io_req->notify.context); |
c8b03afe HM |
529 | } |
530 | EXPORT_SYMBOL(dm_io); | |
952b3557 MP |
531 | |
532 | int __init dm_io_init(void) | |
533 | { | |
534 | _dm_io_cache = KMEM_CACHE(io, 0); | |
535 | if (!_dm_io_cache) | |
536 | return -ENOMEM; | |
537 | ||
538 | return 0; | |
539 | } | |
540 | ||
541 | void dm_io_exit(void) | |
542 | { | |
543 | kmem_cache_destroy(_dm_io_cache); | |
544 | _dm_io_cache = NULL; | |
545 | } |